Iron-mediated oxidative C-H coupling of arenes and alkenes directed by sulfur: an expedient route to dihydrobenzofurans.

A novel route to medicinally-relevant dihydrobenzofurans utilises a sulfur-directed C-H ortho-coupling of arenes and unactivated terminal alkenes mediated by iron, and a palladium-catalysed deallylation/heterocyclisation sequence. The iron-mediated coupling affords linear products of alkene chloroarylation in good yield and with complete regioselectivity. The coupling likely proceeds by redox-activation of the arene partner by iron(iii) and alkene addition to the resultant radical cation.

Iron-mediated C-H coupling of arenes and unactivated terminal alkenes directed by sulfur.

A sulfur-directed Fe(iii)-mediated ortho C-H coupling of arenes with unactivated terminal alkenes gives products of regioselective alkene chloroarylation. The novel mechanism involves redox-activation of the arene partner and alkene addition to the resultant aryl radical cation.